| Webster Groves to Siloam Springs (Arkansas) | 283.03 mi (455.49 km) |
| Webster Groves to Silver Firs (Washington) | 1,709.29 mi (2,750.84 km) |
| Webster Groves to Silver Spring (Maryland) | 717.97 mi (1,155.46 km) |
| Webster Groves to Silver Springs Shores (Florida) | 810.02 mi (1,303.60 km) |
| Webster Groves to Silverdale (Washington) | 1,731.39 mi (2,786.40 km) |
| Webster Groves to Silverton (Oregon) | 1,715.56 mi (2,760.93 km) |
| Webster Groves to Simi Valley (California) | 1,599.89 mi (2,574.77 km) |
| Webster Groves to Simpsonville (South Carolina) | 521.70 mi (839.60 km) |
| Webster Groves to Sioux City (Iowa) | 416.21 mi (669.82 km) |
| Webster Groves to Sioux Falls (South Dakota) | 476.65 mi (767.09 km) |
| Webster Groves to Skokie (Illinois) | 275.24 mi (442.95 km) |
| Webster Groves to Sleepy Hollow (New York) | 889.98 mi (1,432.28 km) |
| Webster Groves to Slidell (Louisiana) | 574.25 mi (924.17 km) |
| Webster Groves to Smithfield (North Carolina) | 694.60 mi (1,117.85 km) |
| Webster Groves to Smithfield (Utah) | 1,151.79 mi (1,853.62 km) |
